Mail stops flowing in exchange 2007 or exchange 2010, in event viewer you see the event id 15006 and The Microsoft Exchange Transport service is rejecting message submissions because the available disk space has dropped below the configured threshold. This can be fixed by moving the mail.que file.
If you have a lot of profiles on your desktops and they are taking up space then follow this guide on how to delete your local profiles on your pc.How to Delete Local Profiles In Windows XP ,vista and windows 7
When promoting a server 2012 domain controller you see this error. Verification of prerequisites for Active Directory preparation failed. Unable to perform Exchange schema conflict check for contoso.local.
Exception: Access is denied.